烧橡胶的刺鼻气味the pungent smell of burning rubber橡胶是稀少而宝贵的, 可是俄国对橡胶的需要量是非常大的.Rubber was scarce and precious, and the Russian demand for it was on the large scale.该光谱表明,聚乙稀类物已经迁移到人造橡胶的表面.The spectrum indicates that a polyethyle...